After starting the mail conversation and telling the server who
the recipient or recipients are, you use the
DATA command to send the body of the message. The
syntax for the DATA command
is very simple:

DATA

After you get the standard 354 response, send the body of the
message followed by a line with a single period to indicate that
the body is finished. When the end of message line is received,
the server will respond with a 250 reply code.

Note
The body of the message can also include several header items like Date, Subject, To,
Cc, and From.